The present invention relates to a Method for operating a vehicle system of a motor vehicle and motor vehicle
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Vehicle systems, in particular driver assist systems which are configured for determining and using a state variable which describes the state of the driver have already been proposed. For example, when a high level of fatigue of the driver is detected, a suggestion to take a break can be issued and/or operating parameters of other vehicle systems can be adjusted to the reduced alertness of the driver. Similar suggestion and adjustment systems are also known with regard to the attention of the driver, wherein for example it is monitored whether the driver pays attention to the traffic or is engaged in secondary activities. Especially in cases in which for example semi autonomous driver assist systems, for example longitudinal guiding systems or transverse guiding systems are used, a system which monitors the attention and/or fatigue of the driver can be useful.
In order to determine the state variable, a broad spectrum of different data is recoded and/or interpreted. It was often proposed to use an interior camera which observes the head and the face of the driver. Here, a model of the head can for example be observed, so that the orientation of the head, the time periods in which the eyes are open and closed, the shut-speed of the eyelids and the like can be determined and analyzed with regard to a state variable. A further example for a sensor whose data can indicate the state of a driver are steering sensors via which the steering behavior of the driver can be monitored. Corresponding pedal sensors are also used. However, environmental data can also be analyzed for example to check how accurately the driver follows the lane, because this also provides indications about his fatigue and/or attention. As can be seen, many different types of sensor data and parameters can be observed to obtain an indication regarding the fatigue and/or attention of the driver.
In order to analyze such a recorded situation data set which describes the behavior of a driver in a defined driving situation, in particular in order to be able to interpret the situation data set in the first place, comparison of the state of the driver to a wake and/or attentive state of driver has to be possible. Only in this way can deviations from this “normal state” be detected and evaluated. For the reliable functioning of the classification and interpretation algorithms, the determination of the norm behavior of the driver is thus required which then corresponds to a reference data set which, as reference state, ideally reflects a normal state. In the state of the art such a reference data set is also referred to as “baseline”. In order to determine the reference data set it is known to use a fixed calibration period at the beginning of every drive in which the actual function of the vehicle system, for example a warning and/or adaption function is not available. During the calibration period, all required and available data are recorded and combined into a reference data set, wherein however, it is not known whether data which describe a normal state are obtained and whether the data quality is sufficient. Thus, very long time periods are used as calibration period. During these long time periods, for example twenty minutes, the actual function of the vehicle system is not available.
A great amount of data is acquired by the described routine for determining the baseline i.e., the reference data set. Special occurrences during the calibration period are not taken into account. Further, disadvantageously, a fixed time window is predetermined for the calibration regardless of whether a sufficient amount of data may already have been acquired. The reliability of the recorded reference data also cannot be ensured. As a consequence, loss of performance of the downstream algorithms for interpreting the state of the driver may occur, because a relevant determination of the driver's state is delayed and/or is based on insufficient base data.
It would therefore be desirable and advantageous to provide an improved to provide a method for operating a vehicle system for quickly and reliably obtaining reference data of a reference data set and to enable to maintain an up to date reference data set.